Variable Response in Alpine Tree-Ring Stable Isotopes Following Volcanic Eruptions in the Tropics and Iceland

Round 1

Reviewer 1 Report

Review of the manuscript “Variable Response in Alpine Tree-Ring Stable Isotopes following Volcanic Eruptions in the Tropics and Iceland” by Arosio et all.

 In the present manuscript, the authors discuss how stable isotopes variability in the cellulose of the tree-ring was affected by the climate fluctuations following major volcanic eruptions over the last two millennia.

The paper is well structured and the information is well presented based on the performed analyses, but it needs some improvements.

The presented here results are interesting and helpful for further studies in the field, therefore I recommend accepting the current paper after minor to moderate revisions.

 

General comments

The aim of the study needs some improvements, in order to eliminate the confusion regarding the analysis period.

The method section has too many subsections and it is hard to follow.

The conclusion section needs to be detailed a bit.

 

Specific comments

L90-93 the analyzed period is the last 2000 years, and the data description needs to be moved to the method part

L 83 (δDfi)? why fi?

L 240 it is not clear between which parameters were made the correlation

L 241 please specify which chronologies were combined

 L 238-244 it is very confusing. Please reformulated or improve. It is not clear why or which chronologies were combined since in the main text the tree species are analyzed separately.

Figure 1 it is hard to understand the site location at the European level

Figure 1 is cited in the text for the first time on line 111 page 3, and until page 9 (where figure 1 is) are cited other 10 figures. It is very hard to read and follow the figures with so many pages in between.

L326 missing “.”

L327 it this a sentence or a subsection title?

L 455 It is not clear the exact period of analyses through the manuscript. Did you analyze the response in alpine tree-ring stable isotopes following volcanic eruptions for the whole Holocene period? if not, this information should be moved to the method part.

L477 “erup-tion”

L478 “tempera-ture”

L479 ” grow-ing”

L483 “temper-atures”

L 488 “We also observed” is used several times in the discussion part

L490 “erup-tion”

L491 “iso-topes”

L495 “Eu-rope”

L500 “erup-tions”

L505 “Neverthe-less”

L511 “spe-leothem”

L521 “fis-sure”

L522 “poten-tial”

L528 “erup-tions”

L533 “spe-leothem”

L533 I am not sure that using the speleothem record in this study brings any new or substantial information

L541 "Al-so”

L550 “lower D values” something missing?

 

Figure S2 I think is not complete

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This is the review for the manuscript of Arosio et al. Overall, the manuscript addresses an interesting topic related to the post-eruptive effect on climate variability. However, the ms. presents multiple weaknesses that prevent me to recommend it for publication. The most important caveat is the difficulty to understand the objectives of the study, the data sources used, the type of stables isotopes analyzed, the tree species used, and the volcanic eruptions target for each data source. The authors assumed that the reader is familiarized with the Alpine Holocene Triple Tree Ring Isotope Record project, and that should not be the case. A more detailed description of that project is needed. I also encourage the authors to write an initial paragraph at the beginning of the methods section stating the sources that they are using for this study. The difficulty to understand the objectives of the project and methods used prevented me to give detailed comments for the results and the discussion sections.

 See below for more specific comments.

-          The abstract needs to be restructure. Please indicate in the same sentence how many volcanic eruptions are analysed in this study, right now that information is all over the place. In line 15, indicate which particular stable isotopes are you using. In line 23 the authors mentioned the post volcanic fingerprint on larch, Did you included different tree species in the study? Which ones? Line 25, the authors mentioned 5 year-resolution data… The species, number of volcanic eruptions included in the study and the resolution used in the analyses should be mentioned earlier in the abstract, followed by the main results and a couple of sentences highlighting the main conclusions.

-          The abbreviation for the chemical components doesn’t use the correct form for subscripts. The Latin name of tree species should also be in italics.

-          L112-116. This paragraph needs clarification. L 112-114, From which period or particular years? L 114-116, Those four trees are also the ones mentioned in lines 112-114? Please indicate clearly: number of trees used, tree species, data resolution, type of stable isotopes used and period analyzed.

-          Section 2.2 should be moved before Lines 112-116à First you measure tree ring widths, next you identify the trees with wide rings and then you run the stable isotopic analyses.

-          L 123. Still don’t know which three isotopes are you using here….please these need to be clearly stated earlier in the manuscript. I see later in this paragraph that they are hydrogen, oxygen and carbon, but please this need to be clearly stated earlier.

-          Section 2.5. Please include at the beginning of the section a sentence indicating the list of the volcanoes.

-          L 187. There is no Table 2 in this manuscript…maybe is Table S1. Please clarify or include the table.

-          L216-219. These should be included in the methods.

-          Figures 2 and 4. The lines are blue, not green. If possible, include smoothing splines for each tree of 5-10 years, leaving the original data points shaded in the back. This may help to determine if there are any trends after the eruptions.

-          Figures 6 and 7. The lines are blue and red, not green and orange (in figs 2 and 4 it was red…be consistent when using the same colors). There is an erratum in x axis in all panels.

-          L239-241. For each Pearson correlation analysis, you need to include the p value.

-          L 327. Is this suppose to be a heading? The sentence is disconnected from the next paragraph.

-          L 358. present different trends

-          L 466. fol-lowed, correct.

-          L 476. construc-tions, correct.

-          L 477. erup-tion, correct. There are multiple types like these ones, please correct all.  

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

This is the review for the manuscript of Arosio et al. Overall, the manuscript addresses an interesting topic related to the post-eruptive effect on climate variability. However, the ms. presents multiple weaknesses that prevent me to recommend it for publication. The most important caveat is the difficulty to understand the objectives of the study, the data sources used, the type of stables isotopes analyzed, the tree species used, and the volcanic eruptions target for each data source. The authors assumed that the reader is familiarized with the Alpine Holocene Triple Tree Ring Isotope Record project, and that should not be the case. A more detailed description of that project is needed. I encourage the authors to write an initial paragraph at the beginning of the methods sections stating the sources that they are using for this study. The difficulty to understand the objectives of the project and methods used prevented me to give detailed comments for the results and the discussion sections.

 

See below for more specific comments.

-          The abstract needs to be restructure. Please indicate in the same sentence how many volcanic eruptions are analysed in this study, right now that information is all over the place. In line 15, indicate which particular stable isotopes are you using. In line 23 the authors mentioned the post volcanic fingerprint on larch, Did you included different tree species in the study? Which ones? Line 25, the authors mentioned 5 year-resolution data… The species, number of volcanic eruptions included in the study and the resolution used in the analyses should be mentioned earlier in the abstract, followed by the main results and a couple of sentences highlighting the main conclusions.

-          The abbreviation for the chemical components doesn’t use the correct form for subscripts. The Latin name of tree species should also be in italics.

-          L112-116. This paragraph needs clarification. L 112-114, From which period or particular years? L 114-116, Those four trees are also the ones mentioned in lines 112-114? Please indicate clearly: number of trees used, tree species, data resolution, type of stable isotopes used and period analyzed.

-          Section 2.2 should be moved before Lines 112-116à First you measure tree ring widths, next you identify the trees with wide rings and then you run the stable isotopic analyses.

-          L 123. Still don’t know which three isotopes are you using here….please these need to be clearly stated earlier in the manuscript. I see later in this paragraph that they are hydrogen, oxygen and carbon, but please this need to be clearly stated earlier.

-          Section 2.5. Please include at the beginning of the section a sentence indicating the list of the volcanoes.

-          L 187. There is no Table 2 in this manuscript…maybe is Table S1. Please clarify or include the table.

-          L216-219. These should be included in the methods.

-          Figures 2 and 4. The lines are blue, not green. If possible, include smoothing splines for each tree of 5-10 years, leaving the original data points shaded in the back. This may help to determine if there are any trends after the eruptions.

-          Figures 6 and 7. The lines are blue and red, not green and orange (in figs 2 and 4 it was red…be consistent when using the same colors). There is an erratum in x axis in all panels.

-          L239-241. For each Pearson correlation analysis, you need to include the p value.

-          L 327. Is this suppose to be a heading? The sentence is disconnected from the next paragraph.

-          L 358. present different trends

-          L 466. fol-lowed, correct.

-          L 476. construc-tions, correct.

-          L 477. erup-tion, correct. There are multiple types like these ones, please correct all.